


Unplanned

by BurntHoneyy



Category: Voltron: Legendary Defender
Genre: Alpha Keith (Voltron), Alpha/Beta/Omega Dynamics, Galra Keith (Voltron), M/M, Smut
Language: English
Status: Completed
Published: 2018-01-21
Updated: 2018-01-21
Packaged: 2019-03-07 16:08:59
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,581
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/13438389
Author URL: https://archiveofourown.org/users/BurntHoneyy/pseuds/BurntHoneyy
Summary: Keith is an alpha with the Blade of Marmora and had joined Kolivan to assist the Paladins of Voltron. When Keith realizes he had forgotten to pack supplies for his fast-approaching rut, Shiro offers to help.





	Unplanned

**Author's Note:**

> This is my Sheith Secret Santa gift! I'm so sorry it's been posted late, I hope you enjoy it.
> 
> Many thanks to my [Beta](http://mothmanwingman.tumblr.com/)! Please checkout her work [here](https://archiveofourown.org/users/MothmanWingman).
> 
> Comments/kudos are appreciated. Thank you for reading! x

“Is there a reason you did not tell me sooner?”

Keith remained quiet, eyes downcast from Kolivan’s harsh gaze. His tail flicked back and forth behind him with his ears pinned back. Keith knew it looked like he was getting a lecture. Frankly, he would prefer the paladins to assume that was the case than to overhear their discussion.

“Keith?”

“...was embarrassed.” Keith mumbled his reply, still staring at the floor.

“We stopped for food and supplies last week. Should you have mentioned something then, I could have made sure to acquire-”

“I know.”

Both Blades were quiet now and Keith knew there was nothing that could be done at this point. His rut was soon approaching and he realized too late he had forgotten to pack his necessities, waiting until the last minute to inform Kolivan. Keith had never experienced a rut without suppressants or omega-scented clothing and he didn’t plan to start now.

The elder Blade sighed and Keith wished he hadn’t even told him. It was embarrassing. On the rare occasions it would happen on the base, Keith could tell Thace or Ulaz and one of them would scour the entire quadrant. But Kolivan wasn’t his dad, he was his commanding officer.

“I’ll see what I can find.”

Keith didn’t wait to be dismissed, turning on his heels without a word. He walked down the hallway with his tail flicking behind him, ears twitching. He wasn’t going to be able to face Kolivan again for a long time after this.

The Blade continued to walk around the Castle of Lions aimlessly, allowing himself to cool down. He was on edge and wanted to avoid running into the paladins, especially Shiro. To say Keith liked him would be an understatement and he was thankful that Kolivan never gave him away.

Keith had to stop himself from scenting the Black Paladin on more than one occasion. The fact that Shiro returned his interest didn’t help the situation and Keith only found himself drawn to the group’s leader more. He was confident, smart, beautiful, and Keith wanted the paladin all to himself.

The Blade was worried about that side of his alpha instincts. Shiro wasn’t his to own, he knew that. But whenever someone would get too close to the Black Paladin, he would find himself growing overprotective and start growling. He’d try covering it with a coughing fit but Kolivan had picked up on his possessive behavior, and that lead to a conversation even more awkward than the one he just experienced.

The sound of metal on metal had Keith’s ears twitching and he found himself walking towards the training room at the end of the hall. A familiar grunt had him pausing before entering, eyes widening as the scent of sweat entered his nostrils. He peeked around the doorway to see Shiro advancing on a bot before kicking it so hard it flew and crashed into the wall.

He wasn’t wearing his armor. Instead, the Black Paladin adorned a pair of black track pants and very sweaty tank top he was currently taking off as he called out to end the training sequence. Keith’s heart sunk at the scars that littered his back and his tail twitched behind him. He managed to suppress the growl that threatened to escape, wanting to tear apart anyone who dared to lay a finger on Shiro.

“Oh, hey Keith!”

Keith’s eyes widened, and upon being spotted by the paladin, rounded the corner and entered the training room. He made sure to keep his distance as Shiro’s scent was far too arousing, the Blade knew there was a strong chance it could trigger his rut early.

“Hello, Shiro… were you finished training?”

Shiro smiled, stretching his arms above his head. “Finished? I’m just getting started. Care to join?”

It was getting harder for Keith to maintain eye contact, so he turned his body towards the doorway. “I can’t. Kolivan asked me to meet him at the ship bay.”

“Oh, so that’s why you were watching me from the door?”

Shiro chuckled as Keith’s cheeks heated up, tail whipping behind him. “I wasn’t watching from the… I was observing your technique, it’s horrible.”

“Is it now?”

Keith hadn’t really noticed how Shiro had been walking closer until he was right in front of him. The delicious scent was becoming more prominent and Keith knew he had to leave, _now_.

“Maybe you should teach me then?”

Keith’s heart was hammering so fast in his chest that he was worried Shiro could hear it. With every breath, more of Shiro’s arousing scent wafted through his nose and blurred his common sense. He knew this was a bad idea. He should leave the gym and head straight to his room, locking himself inside until his rut arrived and he’d spend the next week in pain.

“I have to go.”

Keith forced himself to turn around, pretending that he didn’t see the confusion in the paladin’s eyes. He swiftly left the training room, but as soon as he turned the nearest corner, his ears twitched in annoyance.

“Keith! How’s my favorite furry doing?”

Keith glared at the Blue Paladin. “I asked you to stop calling me that.”

Lance just smiled and approached Keith, the Yellow Paladin trailing behind him but keeping his distance. Keith could tell Hunk was nervous so the Blade made sure to keep his glare pinned on Lance, not wanting to upset the Yellow Paladin.

“Kolivan lets me call him a furry.” Lance folded his arms.

“That’s because he doesn’t know what it means.” Keith lowered his voice, taking a step closer and wiping the smug look off his face. “And he’s very keen on taking you in his bed.”

Not only did Lance’s face pale at Keith’s reveal, his mouth dropped, opening into a small ‘o’ and Hunk gasped. Whether Keith had been reading Kolivan’s body language correctly or not, the Blade didn’t care. He shoved past Lance and continued down the hallway as he made his way to his temporary room.

 

 

Shiro left the showers of the gym’s changing room, still trying to figure out what he said wrong. Keith had left the gym so suddenly and with almost no expression on his face. Had he offended the Blade? No, he couldn’t have. Keith had been acting strange over the course of the past week now that Shiro thought about it.

As he left the gym, the Black Paladin remembered Keith mentioning he had to meet Kolivan in the ship bay. He was about to head over to see if Kolivan knew anything about Keith’s strange behavior, but ran into the Blade leader as the Galra exited one of the guest rooms.

“Oh, Kolivan, do you have a minute?”

Kolivan stopped walking and turned to Shiro. “Hello, paladin. Is there something I can help you with?”

“Well, actually, it was more of a question? Keith’s been a bit… weird lately. Do you know if he’s alright?”

Shiro noticed Kolivan’s body language became guarded and he instantly regretted asking in the first place. Kolivan didn’t answer immediately, shifting his eyes away from Shiro and staring past him and down the hallway.

“Keith is experiencing a personal issue at the moment.”

“Oh, okay. Well, let me know if there’s anything I could do to help.”

“You might be able to provide some assistance…” Kolivan said as Shiro started to turn away. “But we should discuss this in a more private setting.”

Shiro followed Kolivan down the hall and Shiro couldn’t help but be worried. If Kolivan didn’t feel comfortable sharing Keith’s situation out in the open, it must be pretty bad. He was starting to feel horrible for flirting with the young Blade. He could be going through something serious and Shiro didn’t even know about it.

The two reached a room meant for diplomatic meetings and Shiro followed Kolivan inside. The Blade leader locked the door behind them but didn’t sit down, Shiro standing awkwardly as he waited for Kolivan to begin.

“How much do you know of Galra biology?”

Shiro blinked. This definitely wasn’t how he expected the conversation to start.

“Uh, well... “ Shiro cleared his throat but kept the straightest face he could. “I, uh… I guess I don’t know how this would relate to Keith?”

Kolivan didn’t answer immediately, looking at the table for a brief moment before back to Shiro. “I would not be sharing this with you if I was not aware of this, but Keith is interested in you. In Galra biology, there are alphas, betas, and omegas. Are you familiar with this hierarchy?” Shiro barely managed a nod and Kolivan continued. “Are you familiar with terms such as a heat or rut?”

Shiro nodded again and fought hard to maintain his serious expression, and to force himself to keep from blushing. If Kolivan could remain professional for this conversation, so could he.

“Keith… lacks the necessary supplies to endure his rut and as it approaches, it’s been affecting his behavior. I shared this with Coran as well in hopes he would have anything that could help, but he did not.”

The paladin nodded with a faux thinking face as _rut_ echoed in his mind. Keith was an alpha? He was so much smaller than the other Galra Shiro’s seen, though he supposed it made sense why Keith left so suddenly when Shiro invited him to spar. The Blade was probably trying not to jump his bones.

Shiro masked the shiver than ran through him, shifting on his feet. “I guess we could use the scanners to see where the closest space mall would be.”

“I’ve already checked. The closest one is several quadrants away, not to mention in Galra territory. Yes, it would have what he’d need but would prove to be far too great of a risk.”

Shiro frowned. “I’m sorry if I misunderstood, but didn’t you say there was a way I could help?”

“Yes, well… supplies wouldn’t be necessary if someone were to… assist him.”

“Oh. _Oh_.” This time, Shiro couldn’t stop his face from heating up. “Are-are you suggesting that I be the one to, uh, assist him?”

How Kolivan was able to keep a straight face was baffling. Maybe this wasn’t as a taboo topic in Galra culture?

“If you would be willing, I know Keith wouldn’t refuse if you were to offer.” Kolivan paused. “I think I’ve heard the Blue Paladin use the word crush, to describe Keith’s interest in you.”

Shiro blinked. “Lance told you that Keith has a _crush_ on me?”

Kolivan didn’t blush but his ears twitched and Shiro could have sworn he saw his tail flick behind him. The two finished their conversation quickly, Kolivan informing Shiro he would retrieve him when the time came.

 

 

“End training sequence.”

The gym powered down and Keith sheathed his sword. He was breathing hard, sweat dripping down his forehead. The closer he was to his rut, the more aggressive he became. Keith had become fixated on how painful it was going to be since he had absolutely _nothing_.

At the simple reminder, a low-pitched growl left his throat and he quickly started the next training sequence, unsheathing his sword again. Keith continued to take out his frustration on the robots, losing track of time. He had reached level thirteen before exhaustion finally reached him, dropping to his knees after letting it finally come to an end.

“I was wondering when you would stop.” Keith didn’t bother to look at Kolivan as the older Blade lessened the distance between them. “You shouldn’t be out here. Go to your quarters and I’ll bring you the supplies I’ve found.”

“You found something?” Keith looked at Kolivan in disbelief.

“Yes. Go to your quarters and I’ll stop by shortly.”

Keith took a few more deep breaths before getting to his feet and sheathing his sword. As he left the training room, he focused harder than he should have to get to his room successfully. He was sweating, whether it due to the workout or his body preparing itself for a rut, Keith didn’t know.

As soon as he entered, he immediately undressed and headed into the connected bathroom. Even after a cold shower, the alpha pheromones were coming off of him in waves. Keith took a deep breath, clenching his hands hard as he shut his eyes.

He willed away his anger, reminding himself that focusing on the problem wasn’t going to miraculously give him a solution. Keith continued the same breathing techniques until he felt slightly calmer and exited the bathroom. He didn’t bother with clothes seeing as he would just rip them off when the rut started, and frankly didn’t care if Kolivan saw him like this.

He’d already seen him acting like a kit entering puberty when he’d admitted he hadn’t packed his supressives or supplies.

That didn’t matter now. Kolivan was likely on his way to his room now with whatever he managed to gather together in such a short amount of time. Keith threw himself on the bed with a grunt, clutching a pillow to his chest. His tail flicked impatiently behind him as he screwed his eyes shut and willed his body to calm down.

The last thing Keith wanted was to be humping his bed when Kolivan walked in.

It was only minutes later when Keith heard his door opening, and he sat up on the bed. He moved the pillow to cover his crotch and frowned when he saw Kolivan standing in the doorway empty-handed.

“I thought you had something?”

“I do… I explained your situation and he offered to help.”

“ _Who_ offered to help?” Keith’s question was sharp but when a familiar face appeared next to Kolivan, he regretted the tone instantly.

“Hey,” was all Shiro said, Kolivan leaving the moment Shiro entered.

Keith sat there in shock as the paladin locked the door behind him, smiling when he looked back to Keith. Shiro was wearing loose sweatpants and a baggy t-shirt, which he started to pull off but paused when Keith spoke.

“Y-you don’t have to... you shouldn’t... why did you… Are you sure you’re okay with this?”

Keith’s words were jumbled together but Shiro gave a gentle smile, continuing to pull off his shirt. Once it was off, Keith’s eyes traveled over the taut muscle and scarred skin as he barely registered the paladin’s reply.

“I know I don’t have to but if you’ll have me, I’d like to, uh… act as your omega.”

Shiro’s statement lit a fire in Keith and the blush on the paladin’s face deepened as Keith stood up and in an instant, threw him on the bed. He made his way on top of _his_ omega but forced himself to stop, wanting to be certain that Shiro was okay with what was about to happen.

“I… once I start, I can’t stop. If you want to leave, you have to leave now. I’ve never been with anyone else so I don’t how rough I’ll be and I don’t want to hurt you.”

Shiro just gave another smile. “I trust you.”

Keith didn’t know how to react but his body must have, because he began purring. Loudly. It must have surprised Shiro because his smile disappeared and his eyebrows raised but then he started laughing. Keith’s rut wasn’t in full effect yet but he felt it nearing as he basked in his omega’s happiness.

Keith sprawled over Shiro’s body, trying to cover as much of him as possible to keep him warm and protected. He tucked his head into Shiro’s neck and began nibbling at the skin, trying to find the other’s scent gland to mix their smells together. Keith knew he wouldn’t find one but something inside him told him to keep nibbling at the soft skin.

Shiro suddenly keened underneath him and Keith paused, curious. He bit at the same spot and when he received the same reaction, felt heat begin pooling in his stomach. He moved his lips to suck at his omega’s nipples, releasing a growl when Shiro tried arching his back under Keith’s strong hold.

When Keith’s barbed tongue returned to the hard nub, Shiro couldn’t control performing the movement a second time. He gasped when Keith growled louder, pushing one of his hands down on his chest to keep him pressed flat against the bed.

“Don’t move.”

Shiro shivered at Keith’s tone, as it had dropped to a deep rumble. Heat pooled in the paladin’s stomach but he realized that his alpha was displaying dominance over him. He remained still as Keith returned to his attempt at milking his nipples then moaned as he bit down rather roughly.

Keith’s breath was hot as he panted against Shiro’s chest. The Galra pulled back and as his tail flicked behind him, Shiro looking down to see Keith’s cock on full display. It was leaking pre-cum, and much bigger than Shiro would have expected given Keith’s size. A knot rested at the base and before the paladin could second guess his decision, the Galra flipped him onto his stomach.

Rather than pulling off the remaining clothes, Keith ripped the fabric covering Shiro’s ass. Something about the animalistic behavior turned Shiro on further and he found himself presenting his ass high in the air. Shiro was maneuvering his human hand between his legs when he felt the head of Keith’s cock already pushing at his hole.

Shiro was more than glad that he had taken the time to prepare himself before Kolivan retrieved him. There was a slight pain, seeing as Shiro only had his fingers to work with. The paladin moaned as the ridges on Keith’s cock breached his hole, arching his back in what he hoped would come across as a sign of submission.

It must have worked because Keith began rubbing soothing circles on Shiro’s hips. The alpha then leaned forward and licked Shiro’s back, who had to stifle his laughter. It was most likely an attempt to groom him but the action was so ticklish that his body was shaking, and Keith leaned back inquisitively.

His mouth returned to Shiro’s back but this time, planting gentle kisses along raised skin. The paladin felt his muscles relaxing and was shocked to realize that he was tense to be begin with. His breathing slowed down and Keith’s hand move to wrap around his stomach as he laid his cheek against his back.

Keith’s breath tickled his skin and he left a few more kisses before he leaned up, hands returning to grip Shiro’s waist. The alpha pulled out almost completely and all but purred when he slammed in, Shiro gasping. Keith repeated the action, each time thrusting harder and faster until he was pinning Shiro to the bed with a hand on the center of the paladin’s back.

He was ruthless, and Shiro loved every second of it. He tried meeting Keith’s thrusts but any attempt at moving was met with an animalistic snarl. The paladin would be lying if he said it didn’t turn him on further. The front of his sweatpants were soaked and he knew he wouldn’t last much longer, his strokes becoming desperate.

“Shiro… I have to... “ Keith’s hands tightened on Shiro’s hips. “Can… can I knot you?”

Shiro could barely answer seeing as Keith’s pace wasn’t slowing down. “I-nng. W-will I… have y-your, ah... pups?”

When Keith heard the word leave his omega’s lips, he couldn’t help but press his growing knot against the abused hole. “I-I don’t know… I don’t… Y-you can say no.”

Keith was panting as he fought against his alpha’s instinct to breed. Shiro was the perfect submissive omega and painted the prettiest picture beneath him. He would make a beautiful mate, and carrier of his pups.

But the last thing Keith wanted was to force his knot inside him, especially when they both had so many questions. Could Shiro get pregnant? If he did, would he even survive the pregnancy? The birth? How would it even work?

“Knot me, Keith.”

Keith’s tail flicked behind him but he remained still. Had he heard that right?

“Do it.”

“Sh-Shiro? Are… are you sure?”

Shiro moaned and pressed his ass back against Keith, trying to take Keith’s cock deeper. Keith picked up the pace again, feeling encouraged by his omega's display.

“Breed me, alpha. Give me your pups! I want y-your knot inside me.”

Keith’s furious pace returned full force and Shiro was gasping into the pillow as Keith rammed his knot inside him, cum flooding his hole seconds after. Keith grinded into Shiro’s ass, claws unconsciously unsheathing and marking Shiro’s hips. The paladin’s hole clenched around Keith’s cock as he came, moaning broken fragments of his alpha’s name.

“Gonna… breed you.” Keith growled out, pulling Shiro’s hips and trying to get their bodies even closer together. “Fill you with my pups.”

Shiro opened his mouth to reply but all that left was a whimper as Keith pumped his seed inside him. When Keith finished, he wrapped his arms around Shiro as the omega fell flat against the bed. Keith was purring, the rumbling most prevalent where their bodies remained connected.

Keith rested his cheek on his lover’s back, closing his eyes. He deepened his purr, keening when he felt his omega relax further underneath him. He started to lick at Shiro’s back, the sweat an enticing mix of their scents.

Perhaps Keith could survive this week after all.


End file.
